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FOR EQUIPMENT OWNERS ONLY Questions and discussions regarding Commercial BuildingsenMon, 19 Nov 2018 22:46:01 GMTvBulletin60https://hvac-talk.com/vbb/images/misc/rss.pnghttps://hvac-talk.com/vbb/
Dampers In Return Airhttps://hvac-talk.com/vbb/showthread.php?2201541-Dampers-In-Return-Air&goto=newpost
Mon, 19 Nov 2018 20:03:59 GMTI've been trying to do some research on this question but I cannot for the life of me find a valid answer. Could someone please explain to me why it is bad practice to install dampers in return air duct?

Thank you
]]>AOP Commercial HVACdr2430https://hvac-talk.com/vbb/showthread.php?2201541-Dampers-In-Return-Airwhere should I post my question?https://hvac-talk.com/vbb/showthread.php?2201484-where-should-I-post-my-question&goto=newpost
Sun, 18 Nov 2018 00:07:58 GMThey guys,
so confused by the structure of this forum :D
Well I own a little basement and build a sound studio into it, and now I have a question...hey guys,
so confused by the structure of this forum :D

Well I own a little basement and build a sound studio into it, and now I have a question on a pipe I am about to install.
this is the thread I want to put somewhere but I don't know where, I hope you can help me:

Dear planners, builders, enthusiasts,

I hope you can answer a question for the studio I am building.

First, it is going to be my 5.1 mixing, and music and voice recording room, 35m2, 2,6m high. Somebody here in Cologne/Germany is helping me to plan the studio, it is going well so far.
Now I am about to install the HVAC / ventilation system / heat exchanger, that I luckily got very cheap. It is able to move 600m3/h (with heat exchange!), although I will never have it run more than 50%.

I am building it all by myself, so I cant afford a HVAC planner. The way the studio is planned, there is gonna be a huge bass absorber in the front, and one in the back. All around the absorbers I leave a 10cm air gap in every direction, so air can float around them, because most of the walls are outer walls.

The to-air pipe goes all along from left to right behind the back absorber, with air outlets every meter, so the air will evenly spread behind the back absorber.
The exhaust air is going to be led out all along from left to right behind the front absorber, right under the ceiling.

My question is: Which height is best for the pipe behind the back absorber? Should I put it on the floor, so the air stream is diagonal? Or in the middle at 1.20m high? or under the ceiling as well, so the slightly colder air will fall down?

thank you alot in advance,
best
Marcus
]]>AOP Commercial HVACmarcuszilzhttps://hvac-talk.com/vbb/showthread.php?2201484-where-should-I-post-my-questionTrane VAV boxes basically unresponsive to thermostats in commercial environmenthttps://hvac-talk.com/vbb/showthread.php?2201346-Trane-VAV-boxes-basically-unresponsive-to-thermostats-in-commercial-environment&goto=newpost
Thu, 15 Nov 2018 02:52:12 GMTGood evening. I'm coming to this group after basically feeling that I've exhausted a number of the local service options and help from my landlord (which honestly doesn't even really own anything in my unit anyway :) .)

Our current system consists of 4 Trane VAV units attached to a free air system (I think thats what it's called...) There is a large unit on the roof of our building, owned and managed by the landlord, which provides conditioned air to our entire floor (55 degree air, I believe) and the VAV boxes (that I own) are in charge of dampening the cold air in the summer and heating up the cold air in the winter.

At a certain point in time, the landlord purchased an upgraded computer system which would automatically place our VAV boxes into away mode over the weekend, etc and we would have to frequently high-limit reset our VAV units because of communication issues when shutting down the incoming air from the ceiling unit. At some point they decided to de-comission this system... but they did not make any changes to our wiring, etc in our building. It seems as if a lot of the issues happened afterwards.

There have always been issues with our system cooling and heating but for most I have been able to solve with a high limit reset (after turning off the power) or by forcing the damper open for a little while, etc. Earlier in the fall I got our local Trane contractor to come and check everything out to make for sure we were good for the winter and I was told everything looks good... and I probably shouldn't waste my money any longer given that there just isn't much to check since the conditioned air is provided by the landlord.

However... winter showed up today and I just really can't get these boxes to heat up. Here's what the control boards look like:

It just seems like these have to be able to be configured to run independently of each other in a very simple manner. Is there something that I'm missing here? I just want the thermostat to turn to a temp... and for the VAV connected to that thermostat to try to raise the temp to that temperature.

Any thoughts on how to troubleshoot things? I've power cycled the unit, tripped the high-limit reset, and they will heat up for a bit.. but they just always seem to tucker out. It could be that the thermostat is bad.... but seems odd that I would have 4 bad @ the same time.

Thanks much in advance. I've just found this place and it seems like a great resource so guys like me appreciate guys like y'all!

Attached Images

]]>AOP Commercial HVACjasonjollyhttps://hvac-talk.com/vbb/showthread.php?2201346-Trane-VAV-boxes-basically-unresponsive-to-thermostats-in-commercial-environmentTrying to give away a complete 3-phase working 5 ton AC unit in Torontohttps://hvac-talk.com/vbb/showthread.php?2201242-Trying-to-give-away-a-complete-3-phase-working-5-ton-AC-unit-in-Toronto&goto=newpost
Mon, 12 Nov 2018 22:33:17 GMTHi all,
I run a commercial building and we recently upgraded our AC. We have pulled a working 5 ton Lennox 3-phase outdoor air conditioning unit...Hi all,

I run a commercial building and we recently upgraded our AC. We have pulled a working 5 ton Lennox 3-phase outdoor air conditioning unit and a matching single-phase indoor air handler.

I hate to see these units go to landfill/scrap as the are in fine working order. The problem is I can't find anyone via the usual routes (Craigslist and Kijiji) who can use a 3-phase unit.

Any takers or suggestions on where to offer them? They are free to anyone who will pick them up - and promises not to scrap them! They are fully purged and disconnected, ready to be loaded on a vehicle.

But wait! There's more! We have an Armstrong Ultra SX 90 Gas Furnace - 90,000 BTU Model number: GUK100D14-3A available at the same low cost of zero dollars to a good home.

We are located right downtown in Toronto Canada. Postal code: M5A1S2

Many thanks,

Paul
]]>AOP Commercial HVACpbloorehttps://hvac-talk.com/vbb/showthread.php?2201242-Trying-to-give-away-a-complete-3-phase-working-5-ton-AC-unit-in-TorontoIs it time for a service call? Intermitent Bryant problem.https://hvac-talk.com/vbb/showthread.php?2201223-Is-it-time-for-a-service-call-Intermitent-Bryant-problem&goto=newpost
Mon, 12 Nov 2018 16:19:24 GMTOne of my 1998 Bryant 580DPV060 RTUs Has twice not fired up. First time was 1-15-18. I found the unit with the blower running but cold exhaust.
At...One of my 1998 Bryant 580DPV060 RTUs Has twice not fired up. First time was 1-15-18. I found the unit with the blower running but cold exhaust.
At that time I shut off power, checked fuses, then called for repair. When I turned power back on it fired up and worked fine...for the rest of the season.(I cancelled the repair call)

Forward to today. Same problem, unit running, filters less than 3 months old and looking good, no heat. Shut off the disconnect and checked fuses. Turned on the power and it fired up as it should.

Knowing how difficult it is to diagnose intermittent problems, Im wondering if it is worth my time and money to call someone in while the unit is running properly?
]]>AOP Commercial HVACEaglemasterhttps://hvac-talk.com/vbb/showthread.php?2201223-Is-it-time-for-a-service-call-Intermitent-Bryant-problemAmana (low price) vs Daikin and Lennox (high price)https://hvac-talk.com/vbb/showthread.php?2201176-Amana-(low-price)-vs-Daikin-and-Lennox-(high-price)&goto=newpost
Sat, 10 Nov 2018 22:53:39 GMTI got these three quotations.

The Amana is cheaper by a good margin, while offering more heat in winter (3-ton) and still allowing 2-ton equivalent cooling in summer on low stage (for better humidity control).

The XP14 and Daikin DZ14SA are similar prices but higher than Amana, while being single stage 2-ton.

Do you see a reason to justify the Lennox or Daikin higher price? Better built quality, etc.? Or should I just go with the Amana two stage?

Thanks,

Larry.
]]>AOP Commercial HVACLarryMTLhttps://hvac-talk.com/vbb/showthread.php?2201176-Amana-(low-price)-vs-Daikin-and-Lennox-(high-price)3,500 sqft Auto repair shop AC and Heat Questions. Estimates are very different.https://hvac-talk.com/vbb/showthread.php?2201172-3-500-sqft-Auto-repair-shop-AC-and-Heat-Questions-Estimates-are-very-different&goto=newpost
Sat, 10 Nov 2018 18:24:37 GMTHey everyone, I hope this is going in the right place, but I own an Automotive repair shop and in Houston it gets god awful hot in the summers so I...Hey everyone, I hope this is going in the right place, but I own an Automotive repair shop and in Houston it gets god awful hot in the summers so I want to put AC in the shop for my guys and the customers cars. The issue is I am getting Estimates that are VERY far apart and the guys who come out to give the bids, dont seem very sure about what they are quoting.

Building is brand new, insulated very well on the sides and roof (Dont know what grade) 3500 sqft shop space, three roll up doors, and 3 shop entrance doors. I currently have a 14' Big ass fan in the shop now. Ive been told everything from a 5ton unit and if that doesn't work, they can add one more 5ton unit.

I attached a layout of the shop, everything inside the highlighted space is ours, and on the real picture of the shop, the space with the red X, is where there will be a 8' wide entrance into the other side of the shop.

Any thoughts or Ideas would be greatly appreciated so I can hopefully make an informed choice on who to go with.

Thank you!
]]>AOP Commercial HVACSpoooolinhttps://hvac-talk.com/vbb/showthread.php?2201172-3-500-sqft-Auto-repair-shop-AC-and-Heat-Questions-Estimates-are-very-differentTrane SFCA-503-HAhttps://hvac-talk.com/vbb/showthread.php?2201070-Trane-SFCA-503-HA&goto=newpost
Thu, 08 Nov 2018 16:07:04 GMTI am having trouble identifying an old Trane SFCA-503-ha. Can anyone help me this a nomenclature for this unit?I am having trouble identifying an old Trane SFCA-503-ha. Can anyone help me this a nomenclature for this unit?
]]>AOP Commercial HVACdandelinhttps://hvac-talk.com/vbb/showthread.php?2201070-Trane-SFCA-503-HAWalk in freezer drain pan issueshttps://hvac-talk.com/vbb/showthread.php?2201032-Walk-in-freezer-drain-pan-issues&goto=newpost
Wed, 07 Nov 2018 18:07:50 GMTI need a little help with a situation in a walk-freezer and any advice would be greatly appreciated!
Recently, we had a bolt on replacement door...I need a little help with a situation in a walk-freezer and any advice would be greatly appreciated!

Recently, we had a bolt on replacement door installed to fix a sagging door issue. The new door frame is larger than the original opening and covered approximately 3/4 of the pressure relief vent opening. Since the new door was installed, we have been experiencing drain issues in the catch pan under the evap. The water created during the defrost cycle stays in the pan and then freezes solid when the cycle is over. The next defrost cycle adds more water to the already formed layer of ice and eventually overflows the pan. The drain line heater is new and is working and no work has taken place on the drain.

I realize the cabinet will be in a negative and the vent is supposed to equalize the pressure differences. Does the vent affect more than just the door opening and closing? I tend to believe the negative pressure inside the cabinet would keep the water in the pan from draining until the door was opened to equalize the pressures involved.

Is it possible or likely that the blockage of the vent could cause such an issue? My gut says "YES" but I would like a more definitive answer.

Sorry for the "novel" but just wanted to throw in as much info as possible!

Thank you in advance!!!
]]>AOP Commercial HVACLazlarhttps://hvac-talk.com/vbb/showthread.php?2201032-Walk-in-freezer-drain-pan-issuesHitachi FLAhttps://hvac-talk.com/vbb/showthread.php?2201027-Hitachi-FLA&goto=newpost
Wed, 07 Nov 2018 13:20:42 GMTHi!
I am a New Maintenance Engineer in charge of a Hitachi RUA-30AT3S type Air Conditioning Unit. What is stated in the nameplate for its FLA is...Hi!

I am a New Maintenance Engineer in charge of a Hitachi RUA-30AT3S type Air Conditioning Unit. What is stated in the nameplate for its FLA is 17.5A however, what I am getting from my reading is 19A -21A. Can somebody explain what is really the FLA of this Air conditioning unit? I have recently discovered 1 compressor motor unit to be overcurrent, but the readings of the said compressor is lower than others.

Thank you for reading and if you can share your thoughts, it would be greatly appreciated :)
]]>AOP Commercial HVACSamanthahttps://hvac-talk.com/vbb/showthread.php?2201027-Hitachi-FLABulldogs freezerhttps://hvac-talk.com/vbb/showthread.php?2200976-Bulldogs-freezer&goto=newpost
Tue, 06 Nov 2018 11:05:05 GMTHello Bulldog and everyone on hvac talk. I have had that same problem with a freezer i worked on. You are over charged. Return gas back to...Hello Bulldog and everyone on hvac talk. I have had that same problem with a freezer i worked on. You are over charged. Return gas back to compressor needs to be below 60 degrees. Sub cooling on equipment is crucial. Range 5-10 degrees. Pull out the gas you put in and open tx valve. You will see return gas down and subcooling go down. You may need to pull out more gas to get 20 degrees s.h. at compressor and your 5-10 range on subcool. Site glass needs to be clear when you adjust tx valve. Give valve 20-30 mins to settle out before adjusting again. Sorry so long winded good luck
]]>AOP Commercial HVACDozer3033!https://hvac-talk.com/vbb/showthread.php?2200976-Bulldogs-freezerBMS Evaluationhttps://hvac-talk.com/vbb/showthread.php?2200934-BMS-Evaluation&goto=newpost
Mon, 05 Nov 2018 07:47:01 GMTHi,
I am currently trying to evaluate between various BMS solutions in the market. I am new to the industry and would like to know the best...Hi,

I am currently trying to evaluate between various BMS solutions in the market. I am new to the industry and would like to know the best possible solution. My client owns about a large number of residential buildings spread across many acres in the US. Their current set up consists of Tridium BMS with JCI's facility explorer controllers (FX 60 and PCG/PCX). We as a company are tasked with evaluating the current set up and also suggest changes if necessary.

I have done a preliminary study of with the help of brochures of JCI Metasys, Honeywell EBI and SE Ecostruxure.
Are there any pointers to evaluate the solutions in the market? Can someone tell me the pros and cons of the current implementation given the use cases above? Also, we do not have HVAC in scope, should that have an impact in choosing a solution?
]]>AOP Commercial HVACControlQhttps://hvac-talk.com/vbb/showthread.php?2200934-BMS-EvaluationIs one AC system better than the otherhttps://hvac-talk.com/vbb/showthread.php?2200803-Is-one-AC-system-better-than-the-other&goto=newpost
Thu, 01 Nov 2018 15:49:14 GMTI have quotes on two different AC systems (to be fitted into existing HV). Both contractors have very good reputations in the area and will do a...I have quotes on two different AC systems (to be fitted into existing HV). Both contractors have very good reputations in the area and will do a good job with the installation.
Is one system clearly better than the other? Or are they essentially comparable.

Much thanks!
]]>AOP Commercial HVACbldgownrhttps://hvac-talk.com/vbb/showthread.php?2200803-Is-one-AC-system-better-than-the-otherDesigo CC applying a template to somethinghttps://hvac-talk.com/vbb/showthread.php?2200729-Desigo-CC-applying-a-template-to-something&goto=newpost
Tue, 30 Oct 2018 21:43:40 GMTSo i have a room on site that is using a non editable template graphic. i was able to make a new template graphic in the L4 project folder. How do i...So i have a room on site that is using a non editable template graphic. i was able to make a new template graphic in the L4 project folder. How do i now apply the graphic to the room, or modify the original graphic to show supply air temp.
]]>AOP Commercial HVACGlennZhttps://hvac-talk.com/vbb/showthread.php?2200729-Desigo-CC-applying-a-template-to-somethinghttps://hvac-talk.com/vbb/showthread.php?2200715-Please-give-steps-for-Psychrometric-analysis-for-quot-High-LH-and-No-Return-Air-quot-system&goto=newpost
Tue, 30 Oct 2018 08:32:31 GMT> SH
2. No return air is allowed, hence 100% fresh air is to be supplied.
*I...]]>I am designing a HVAC system for the following conditions,
1. LH >> SH
2. No return air is allowed, hence 100% fresh air is to be supplied.

I want to find the capacity of HVAC system and CFM requirement.

I have the following input data
1. Ambient and room DBT
2. Room area or volume
3. Sensible heat load and latent heat load

Please tell me the steps.

Also what should be exhaust requirements and how to calculate it??
]]>AOP Commercial HVACsohamdhttps://hvac-talk.com/vbb/showthread.php?2200715-Please-give-steps-for-Psychrometric-analysis-for-quot-High-LH-and-No-Return-Air-quot-system